Press for pressing hollow bronze objects



May 17 19247.

A. SCHMITZ Pimss Fn PREssIG aoLLow RoNzxa OBJECTS `F11d sept. a. .1925

llilllllsi Patented May f 1 7, A1927.

UNITED STATES PAT-ENT, OFFICE.

ALWIN SCHMITZ, OF ERFURT, GERMANY.

PRESS FOR PRESSING EIOLLOW BRONZE OBJECTS.v

Application led September 8, 1925. Serial No. 55,114.

acterized by the fact that-'a countersocket` arranged within the matrix and subjected to brake act-ion piesses against the material as the material rises in the matrix under the pressure of the punch so as to prevent the material from tearing while at-thc same time condensing it. The counterrnember within the -matrix is subject to the retardative action of a screwl spindle brake. At the moment when the punch actuated by the press spindle acts upon the lbronze to be pressed thev countermember presses upwardly against a, pressure plate resting on it, so

that the latter, together' with a braking beam suitably connected with it is pushed up. Loosely arranged in the pressure frame,

at eachside of the ,brake beam, is a screw spindle, each of which is provided with correspondingly vertical threads, the said screw spindles being adapted to rotate in stationary bearings of the brake beam. Then the brake beam is moved upwardly the brake action of the screw spindles in the bearings of this brake beam causes eounterpressure to be applied tothe workpiece to be pressed and this counterpressurecontinues to slowly and uniformly applied bylthe turning movement of the spindles in their bearings so longI as the brake beam moves upwardly until the work piece is finished.

The hollow object to bev pressed is there- .fore subjected to uniform and unvarying counterpressure from beginning to the end of the operation on same, -so lthat. any tearing or cracking of the work piece is etlectively prevented.

Any known form of'ejecting device may be arranged on the ram of the press and extend through the bed of the press in known manner for the purpose of ejecting those work pieces that stick to the inatrix.

All attempts hitherto made to produce perfect hollow bodies of bronze b v means of pressing have been i'n vain. Vhile pressing has been successfully ap lied to other metals, such as brass, the pro uction of hollow bodies of bronze has always Vbeen thwarted by the peculiarity of the matelrial. When an attempt is n'ladc by known methods to press hollow bodies out of bronze the edges of the bushings etc. to be pressed usually tear and crack, whereas hollow bronze bodies made by a. press according to the present invcntiondo not reveal those drawbacks but remain whole and free from cracks; they are even improved in so far as the materialis condensed during the-pressing process. After being pressed they can be used at once without any finishing work except for a thin bottom which must be ejected by a special press in a simple and known manner. The press of the present invention, therefore, represents an advance in the art.

One form ofthe invention is illustrated in the accompanying drawing which shows a side view and a partial longitudinal section of the press, Fig. 1 showing the position of the parts before the lpressing begins; Fig. 2showing the position of the parts when the pressure ceases, and Fig. 3 being a plan view of a stripper.

The press is of the known type of friction stamping presses and consists of the press frame 1, the spindle 2 and the bar 3. The spindle 2 is held in the bar in the known manner and is driven at its upper end by a friction discprovided with engaging and disengaging device of the known type. The members'actuating the engaging and automatic disengaging devices .after pressing are' also of known construction and for that reason not shown or described here. The attachment ofthe punch 4 toI the bar 3 may also be accomplished in any known and desired manner. v

In the press frame 1 to the right and left of the press spindle 2 and between the upper part 1 and the bed 1b brake spindles 5 are arranged. .The 'upper and lower ends of the brake spindles 5 bear against balls 6 or other suitable ball bearings. The bar 3 and brake beam 8`move vertically between the side members 1 of the press .on guides formed on said members, and the press spindle 2 slides through an opening formed .in the brake beam. The screw threaded )ortions of the spindles 5 work in threaded ushings 9 which are firmly and immovably arranged in the brake beam 8. The striking rods 10 are also fastened to the brake beam 8 by means of the nuts 11 and without' friction through the holes 12 in the bar- 3. The rods 10 carry on-their lower ends the .pressure plate 14 which is pro-l pass vided with stiifening ribs 13. By means/ofy `any suitable adjusting device, not ;shown,

the brake beam 8 and the pressure plate 14, which, on account of their own weight, always tend to descend while turning the loose spindles 5, can be fixed in any position. vTo the bed 1b of the press frame 1 the matrix is secured in any` desired way.

In the present embodiment ot the invention the matrix 15 has a somewhat conical circumference and rests in a socket 16 which is also'o conical shape. 'lhis Socket 16 is fitted in the matrix casing 17 and is firmly and immovably kept therein by the threaded ring .18. Rotatably arranged on the matrix casing 17 by means of the screw 20 is the stripper 19 having a form shown in Fig.

A 3. By means of the screw 21 the stripper countersocket 23 and the stripper ring 25.

ed in the The press constructed according to the present invention functions las follows:

After securing the brake beam 8 against movement by means ofy any suitable adjusting device in its approximately highest position a bronze disc 24 is placed in the matrix 15, the stripper ring 25 placed on top of the bronzel plate 24 and the stripper 19 clamped ing 17 by the screw 21 to the matrix cas- The countersocket 23 is then insert-- hole 22 of the stripper 19 and the securing device of the brake beam 8 released so asto permit ,thel latter to move downward by its own weight While turning the loose spindles. 5 until the pressure plate 14 rests on the countersocket 23. rIhen the press spindle 2 is set. in motion, which causes the punch 4 to move through the countersocket 23 towards the bronze plate 24 which is to be pressed. The downward pressure thus applied to the bronze plate 24 causes it'to rise at the circumference of the punch 4 and to lift. up the countersoeket 23, the pressure plate 14 and the brake beam 8 over the stripper ring 25. As the lifting of the brake beam S causes the spindles 5 to (urn so that. a certain amount-ot power is consumed in turning them, their rotation causes countcrprossuri` io be applied via the brake beam S and the pressure plate 14 to the eountersocket material .of the work piece. pressure is increased weight of the pressure plate 14, the Striking 4During this backward 23 and also to the risingv This counterto the extent of thev rods 10 and the brake beam 8. The counters' pressure canbe adjusted according tothe strength of the material to be pressed and the wall thickness of the hollow body tobe formed. This 'can be very simply done by providing the spindles 5 withthreads having a smaller or ing the press spindle 2 is posite direction in the known manner and automatically 4 tends to take the `Apressed hollow body with it and thus loosens it in the matrix 15. 'But as the diameter of the hole 22 of the stripper 19 is smaller' than the external diameter of the stripper ring 25 and as the pressed hollow body has been previously loosened in the matrix, the hollow body will be stripped off the punch 4 when the stripper ring 25 strikes the stripper 19. The brake beam 8 is then lifted by means of the adjusting device, ythe countersocket 23 removed, the stripper 19 turned away from the matrix casing 17 in lateral direction and the pressed hollow body with the stripper ring 25 lifted out of the matrix 15 by means of tongs. By putting in low body of equal dimensions can then be made. y

Although the manufacture of hollow bronze bodies is extraordinarily simplified and cheapened by the method described, it is nevertheless impossible to punch the bronze plate through, i. e., to produce it with a hole passing through it; a very thin bottom remains which, however, can be easily cut out in a simple way after the work piece has been removed from the matrix.

lThe above described press presses hollow bodies of any shape out of bronze of any metal composition and produces objects that occupies its highestposition. 'l

movement the punch larger pitch. `After pressrotated in the op` a new bronze plate another holcan be used at once after the thin bottom left therein after pressing has been Stamped out.

The bronze used for these articles is preferably. east in chill moulds so as to form bars and then cut into plates of suitable height. Y

I claim 1. A press comprising a matrix for determlmng` the cross sectional dimension of the object to be formed, a counter-socket arranged within said'matrix and adapted to rise against the pressure of the' extruded material as the latter rises iii the matrix under the 4pressure of a punch', and brake means exercising a retardative control upon the rise of said counter-socket and imposing a counter-pressure' upon the extruding material s as prevent said material from cracking and at the same time condensing it.

2. A press for forming hollow objects' comprising a matrix for determining the cross sectional dimensions of the object to be formed, a counter-socket arranged within said matrix and adapted to riseagainst the pressure of a punch, and a screw spindle brake operatively associated with said counter-socket exercising a retardative control over the rise of said counter-socket for imposing a counter-pressure upon the extrudingr material so as to prevent it from cracking and at the same time condensing it.

A press for forming hollow objects, comprising a matrix for determining the cross sectional dimensions of the object to be formed, a counter-socket arranged Within said matrix and adapted to rise against the pressure of the extruded material as the latter rises in said matrix under the pressure of a punch, a brake beam, a pressure plate associated with said brake beam and adapted to bear against said counter-socket, and screw spindles threaded into said brake beam and rotating in response to the reciprocatory movement thereof to apply counter-pressure through said brake beam and pressure plate to said socket, thereby exercising a retardati've control over the rise of said counter-socket and imparting a counter-pressure upon the eXtruding material so as to prevent it from cracking and at the same time condensing it.

In testimony whereof I aiix my signature.

ALWIN sornarrz.` 

